This invention relates to monocyclic .beta.-lactam compounds and to a process for the preparation thereof. In particular, this invention relates to N-mono or di-substituted-methyl azetidin-2-ones and related compounds and to a method for the preparation thereof which comprises the cyclization of a .beta.-hydroxy or .beta.-halo N-mono or di-substituted-methyl amide. The compounds of the invention are useful intermediates in the preparation of monocyclic .beta.-lactam antibiotics, .beta.-lactamase inhibitors, and bicyclic .beta.-lactam antibiotic compounds.
The class of .beta.-lactam antibiotics includes the well-known penicillin and cephalosporin antibiotics. Newer types of .beta.-lactam antiobiotics have been discovered of late, for example, thienamycin, nocardicin, clavulanic acid, isoclavulanic acid, and monobactam (Belgium Pat. No. 887,428). Because of the importance of the .beta.-lactam antibiotics, there is a need for improved methods for their production and considerable research is being conducted to develop simple and economic routes of synthesis.